Oligopeptides with Equal Amounts of l- and d-Amino Acids May Prefer a Helix Screw Sense
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- 作者：Yosuke Demizu ; Hiroko Yamashita ; Norikazu Yamazaki ; Yukiko Sato ; Mitsunobu Doi ; Masakazu Tanaka ; Masaaki Kurihara
- 刊名：Journal of Organic Chemistry
- 出版年：2013
- 出版时间：December 6, 2013
- 年：2013
- 卷：78
- 期：23
- 页码：12106-12113
- 全文大小：508K
- 年卷期：v.78,no.23(December 6, 2013)
- ISSN：1520-6904
文摘
We investigated the preferred conformations of two nonapeptides, Boc-(l-Leu-d-Leu-Aib)3-OMe (2) and its enantiomer Boc-(d-Leu-l-Leu-Aib)3-OMe (ent-2), four dodecapeptides, Boc-(l-Leu-d-Leu-Aib)4-OMe (3), Boc-(l-Leu-Aib-d-Leu)4-OMe (4), Boc-(Aib-l-Leu-d-Leu)4-OMe (5), and Boc-(l-Leu-Aib-d-Leu-Aib)3-OMe (6), and a decapeptide, Boc-l-Leu-(d-Leu-l-Leu-Aib)3-OMe (7), in solution and in the crystalline state. The nonapeptide 2 formed a right-handed (P) 伪-helix, and its enantiomer ent-2 formed a left-handed (M) 伪-helix. The dodecapeptides 3 and 5 were folded into (P) helices, and 4 formed an (M) helical structure. As for 6, roughly equivalent amounts of (P) and (M) helices were observed in solution, and two (M) 伪-helices were detected in the crystalline state. Furthermore, the decapeptide 7, which possesses four l-Leu residues and three d-Leu residues, was folded into an (M) 伪-helix.